class CommentVariablePerCommentType

class CommentVariablePerCommentType extends CommentVariable {
    
    /**
     * Retrieves the values of the comment variables grouped by comment type.
     *
     * @return array
     */
    protected function getCommentVariables() {
        $node_types = parent::getCommentVariables();
        // The return key used to separate comment types with hidden subject field.
        $return = [];
        foreach ($node_types as $node_type => $data) {
            // Only 2 comment types depending on subject field visibility.
            if (!empty($data['comment_subject_field'])) {
                // Default label and description should be set in migration.
                $return['comment'] = [
                    'comment_type' => 'comment',
                    'label' => $this->t('Default comments'),
                    'description' => $this->t('Allows commenting on content'),
                ];
            }
            else {
                // Provide a special comment type with hidden subject field.
                $return['comment_no_subject'] = [
                    'comment_type' => 'comment_no_subject',
                    'label' => $this->t('Comments without subject field'),
                    'description' => $this->t('Allows commenting on content, comments without subject field'),
                ];
            }
        }
        return $return;
    }
    
    /**
     * {@inheritdoc}
     */
    public function fields() {
        return [
            'comment_type' => $this->t('The comment type'),
            'label' => $this->t('The comment type label'),
            'description' => $this->t('The comment type description'),
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getIds() {
        $ids['comment_type']['type'] = 'string';
        return $ids;
    }

}